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iiNiTED srAgEgsgrArE QFFICE.

I. o. STERN, oF rriiLADELPHiA, PENNSYLVANIA, ASsiGNoR Cro HIMSELE AND GEORGE w.

' STONE, or SAME PLAGE.

STEAM-BOILER.

Speccation of Letters Patent No. 22,834, dated December 14, 1858.

To all whom it may concern:

Be it known that I, IsAAo C. STERN, of the city of Philadelphia and State of Pennsylvania, have invented a new and Improved Mode of Heating FeedVater for Steaming' with one of the pumps as well as with' the interior of the boiler, the opposite coils communicating with each other, and the whole being arranged substantially in the manner set forth hereafter, so that the cold water from the pumps, prior to its passage into the boiler, may be raised to a high temperature, and obviate the well known injurious effects resulting from the usual mode of injecting cold jets of water into the boilers.

In order to enable others skilled in the art to make and use my' invention I will now proceed to describe its construction and operation.

On reference to the drawing, which forms a part of this speciiication, Figure l, represents an exterior view of an ordinary locomotive steam boiler. Fig. 2, the same with the rebox and a portion of the body in section. Fig. 3, a transverse, sectional elevation on the line l, 2, (Fig. 2). Fig. 4, an inverted plan view of the firebox.

Similar letters refer' to similar parts throughout the several views.

A is the body of the boiler, B the chimney and C the fire-box, all of which may be of the ordinary form yand construction.

Two of the ordinary check valves a, and a are secured one to each side of the lire box, each valve being connected to one of the feed pumps in the usual manner. The

- force pipe 5, from the check valve a, passes through the water space on one side of the ire-box, on the inside of which 1t assumes the zigzag or coiled form, represented in Fig. 2, the coil being in close contact with the side of the lirebox. The force pipe o', from the check valve a, passes through the water space on the opposite side of the fireboX, and inside the latter also assumes the form of a coil similar to that on the opposite side. Both coils terminate at, and communicate with the water space of the boiler, the coil at the point a?, and the coil o at the point A pipe el, fitting against the inside of the iirebox, forms a communication between the opposite coils.

As the feed water from the pumps must pass through the whole length of each coil before it can enter the boiler, and as the coil is exposed directly to the lire, it is evident that the temperature of the water must be raised to a degree dependent upon the length of the coil, before it can enter the boiler. The effect of this preparatory heating of the feed water, as a means of economizing the consumption of fuel, is too well known to engineers to require explanation here. It is indispensable that both coils should invariably be filled with water, otherwise the pipes which lforni the same would be soon destroyed by the action of the lire. The pumps of locomotives being single acting, jets of water are injected into the boiler at rapid intervals, and between these intervals, the coil would be momentarily exposed to the deteriorating action of the fire, were it not for the communicating pipe d. As the pump on one side injects its water at different intervals to that on the opposite side, and as the two coils are connected together by the branch pipe d, it is evident that a free circulation of water will be maintained throughout the interior of both coils as long as the pumps are in operation. I/Vhen the operation of the pumps ceases, the coils will be filled with water from the boiler and will, consequently, resist the injurious action of the lire.

I do not desire to claim broadly the heating of the feed water, by allowing it to pass through tubes in tlie fireplace, as such a plan has been heretofore devised; but

I claim and desire to secure by Letters Patent,

The application to locomotive boilers of the arrangement of tubes herein described, that is to say, the arrangement of the coil Zi or its equivalent on the inside on one side of the firebox, and the coil b or its equivatimes, circulate through both coils, as herein 10 lent on the opposite side, when one coil coml set forth. municates With one pump, and the opposite l In testimony whereof I have signed my coil with the other pump of the engine, and name to this specification before two suba when the opposite coils are connected to- Scribing Witnesses.

gether by the pipe d, so that the cold Water, ISAAC C. STERN. direct from the pumps may pass into the .Wtnessesz coils, and thence in a heated state into the f HENRY I'IoWsoN,

boiler, and so that the Water may, at all Y HENRY ODIORNE. 

